Silene thyrsiantha F.Jafari, Mirtadz. & Keshavarzi, 2023

Jafari, Farzaneh, Keshavarzi, Maryam, Doostmohammadi, Moslem & Mirtadzadini, Mansour, 2023, Two new chasmophytic species of Silene (Caryophyllaceae, sect. Siphonomorpha) from Iran, European Journal of Taxonomy 860, pp. 42-61 : 49-52

Silene thyrsiantha F.Jafari, Mirtadz. & Keshavarzi sp. nov.

urn:lsid:ipni.org:names:77313980-1

Figs 1–3 , 5 , 6A‒C ; Table 1

Diagnosis

Silene thyrsiantha sp. nov. differs from S. parrowiana in having viscid stems (vs not viscid), a thyrsoid synflorescence with few flowers, secondary axes mainly with one flower (vs more than three), pedicel length ((4.5‒) 5‒16 mm vs 1‒4 mm), calyx length (8‒10 mm vs 7‒8 mm), and anthophore length (3 mm vs 2‒3 mm) ( Table 1 ).

Etymology

The specific epithet refers to the form of the inflorescence: a thyrsoid synflorescence with one-flowered secondary inflorescences.

Material examined

Type IRAN – Isfahan • north of Semirom on the rocks; 31.422412° N, 51.572952° E; alt. 2530 m; 26 Sep. 2014; M. Mirtadzadini 2089; holotype: MIR! ; isotype: TARI!. Genbank: LC710550 (ITS) and LC710552 (rps16) .

Description

Perennial plants, glabrous, internode viscid. Stems 33.5‒35.5 cm tall, pale green, glabrous, viscid, internodes 14–32 mm long. Basal leaves 14‒20× 2.5‒4 mm, oblanceolate, base attenuate, acute, apex shortly mucronate, glabrous, minutely ciliate margins, glaucous; cauline leaves oblanceolate to linear, acute, apex acuminate, 7–20× 0.5–2 mm, often glabrous. Synflorescence thyrsoid with few flowers, secondary inflorescences with one flower, pedicels (4.5‒) 5‒16 mm long, glabrous. Bracteoles small, lanceolate, 1–1.5 mm long. Calyx narrow cylindrical, 8–10 mm long, glabrous, coriaceous; teeth membranous at margin, triangular, 2 mm long, two teeth acute with narrow transparent margin, other three teeth slightly broader, rounded, and with broad transparent margin. Petals yellowish (when dried), claw 5–5.5 mm long, with broad lateral margins, glabrous, without coronal scales; limb 5–5.5 mm long, linear, bifid to base. Anthophore 3 mm long, puberulent. Mature capsule 5.5‒6× 3‒3.5 mm, ovoidoblong. Seeds 0.8× 0.6–0.7 mm, basically reniform, seed testa cells elongate with V-shaped margins.

Distribution and habitat

Silene thyrsiantha F.Jafari, Mirtadz. & Keshavarzi sp. nov. grows on stony rocks in central part of Iran near Semiron in the Isfahan Province at an altitude of about 2500 m.

Remarks

In the ITS phylogeny, S. thyrsiantha F.Jafari, Mirtadz. & Keshavarzi sp. nov. is a member of a wellsupported, but unresolved, group with S. ghahremaninejadii , S. penduliflora F.Jafari, Keshavarzi & Doostm. sp. nov., S. ruprechtii (MK559501, MN420835), and S. shahrudensis . The occurrence of single nucleotide polymorphisms (SNPs) leads to the variation of branch length ( Fig. 1 , PP=1, MLB =100%). However, S. thyrsiantha is the closest relative of S. penduliflora sp. nov. in the rps16 tree ( Fig. 2 , PP=1, MLB =96%).

Silene thyrsiantha F.Jafari, Mirtadz. & Keshavarzi sp. nov. and S. parrowiana grow in the same rocky habitats. They are similar in having a compact caudex, glabrous stem, thyrsoid synflorescences and coriaceous calyx. Petal limbs are bifid to base and claws without coronal scales. However, they are different in geographical distribution (Semirom in Isfahan Province is about 650 km away from Bisotun in Kermanshah Province). The stems of S. thyrsiantha are viscid while they are non-viscid in S. parrowiana . Both calyx length and pedicel length in S. thyrsiantha are longer than in S. parrowiana . The secondary inflorescences in S. thyrsiantha are mainly one-flowered while the number of flowers in the secondary inflorescence are more than three in S. parrowiana . The inflorescence looks lax with less flowers in Silene thyrsiantha compared to S. parrowiana . Cauline leaves are shorter than leaf internodes in Silene thyrsiantha while they are often larger in S. parrowiana .

Silene thyrsiantha F.Jafari, Mirtadz. & Keshavarzi sp. nov. is distributed in Semirom which is about 300 km from Khamin Mountain in Kohgiluyeh and Boyer-Ahmad Province, and 800 km from Shahrud in Semnan Province. The new species differs from S. shahrudensis in leaf apex (acute or acuminate vs rounded), cauline leaf size (14‒20 × 2.5‒4 mm vs 15‒35× 2.5‒6 mm), pedicel length (4.5‒16 mm vs 6‒12 mm), thyrsoid synflorescence (thyrsoid vs lax thyrsoid; the number of nodes and length of internodes are different), petal limb (linear vs oblanceolate), claw indumentum (glabrous vs ciliate), and seed size (0.8 ×0.6–0.7 vs 1.1× 0.8 mm; margins of the testa cells V-shaped vs U-shaped). The holotype of S. ghahremaninejadii was not available at TARI when the first author visited the herbarium. The morphological comparison between S. ghahremaninejadii and S. thyrsiantha was conducted using information from the protologue ( Table 1 ).

Figures

Fig. 1. 50% majority-rule consensus tree obtained from the Bayesian inference analysis of the nrDNA ITS sequences in selected species of Silene L. Posterior probabilities (PP) ≥ 0.70 are shown above the branches and Maximum likelihood bootstrap (MLB) values ≥ 70% below. Accessions newly sequenced are indicated by a star. Accessions of S. ruprechtii Schischk. (MN420835 and MK559501) are misidentified by Bahmani et al. (2020).

Fig. 2. 50% majority-rule consensus tree obtained from the Bayesian inference analysis of the cpDNA rps16 sequences in selected species of Silene L. Posterior probabilities (PP) ≥ 0.70 are shown above the branches and Maximum likelihood bootstrap (MLB) values ≥ 70% below. Accessions newly sequenced are indicated by a star. Accessions of S. ruprechtii Schischk. (MN460318 and MN460319) are misidentified by Bahmani et al. (2020).

Fig. 3. Distribution map of S. ghahremaninejadii Hoseini & Assadi (blue dot), S. parrowiana Boiss. & Hausskn. (green dots),S. penduliflora F.Jafari, Keshavarzi & Doostm. sp. nov. (red dots),S. shahrudensis Rech.f. (black dot), and S. thyrsiantha F.Jafari, Mirtadz. & Keshavarzi sp. nov. (purple dot). The map was made with QGIS ver. 3.22.9.

Fig. 5. Silene thyrsiantha F.Jafari, Mirtadz. & Keshavarzi sp. nov. (holotype, M. Mirtadzadini 2089; MIR!).

Fig. 6. A–C. Silene thyrsiantha F.Jafari, Mirtadz. & Keshavarzi sp. nov. (M. Mirtadzadini 2089; MIR!). A. Seed. B. Calyx. C. Petal. – D–F. Silene penduliflora F.Jafari, Keshavarzi & Doostm. sp. nov. D. Seed (M. Doostmohammadi & A. Ghorbanalizadeh 4054; MIR!). E. Calyx. F. Petal (M. Doostmohammadi 4056; MIR!). Seeds were scanned with a Dino-Lite digital microscope AM413T model.